Respuesta :

thompzac
To solve this problem just do the following, 
x+9=-12
   -9    -9
x=-21
Check
-21+9=-12 = True 

Hope this helps!=) 
Exvited
x + 9 = -12 equals x = -21.

First, subtract 9 from both sides. / Your problem should look like: x = -12 - 9.
Second, simplify -12 - 9 to get -21. / Your problem should look like: x = -21, which is your answer.